Amputee Resources: Liner Basics 101 | Lesson 1
Learning everything you need to know about your amputation and prosthesis can be overwhelming. WillowWood is here to break it down.
What Does a Liner Do?
Prosthetic liners serve two basic functions: skin protection and suspension of the limb. They are made of three base materials that aid with this function: urethane, silicone, and thermoplastic elastomer (TPE).
Urethane acts and feels similar to human skin. It moves when weight is put on it, thinning at the bone and thickening around muscle.
Silicone is a readily available material that has been used in the medical field for years because of its protective qualities for skin and durability, making it a viable material for liners.
TPE is derived from thermoplastic in a gel form. It provides a skin-friendly quality and protection while also providing cushioning from shock absorption.
The Evolution of Liners
Originally, all liners were tubular and had one thickness of TPE gel, silicone, or urethane throughout the inside of the liner. Today, liners are designed to accommodate common amputation shapes in prosthetics. These amputation shapes are largely determined by the surgical procedure performed.
These newer patterns of thickness throughout the inside of liners serve to make wearing the liners more comfortable. The internal patterns of thickness are called liner profiles.
For more information on liner profiles, be on the lookout for our next Liner Basics 101 blog coming soon!
Prosthetic Terms You Might Not Know
Prosthetics industry jargon can be confusing. Below is a list of commonly used terms that you might be hearing from your clinician.
Anterior: the front surface of a biologic structure
Posterior: the rear surface of a biologic structure
Proximal: closer to the central portion of the body
Distal: the end that is farthest from the central portion of the body
Donning: putting a prosthesis on
Doffing: taking a prosthesis off
Locking: a liner with the a built-in screw thread at the end for use with a lock type suspension (usually a pin lock)
Cushion: a liner without a built-in screw thread at the end
Profile: the pattern and thickness of the gel or silicone inside a liner
Tibial Crest: front apex ridge of the tibia
Fibular Head: outside bony prominence at the top of the fibula where it meets the knee
For a more complete list of terms, click here.
NOTE: Always contact your clinician for prosthetic care advice. The above descriptions are available to help you get started in choosing which option may be best suited for you, but should never replace prosthetic advice from your clinician.
4 responses to “Amputee Resources: Liner Basics 101 | Lesson 1”
When you use a liner with a knee sleeve , sometimes the socket border tears the liner. Would you have some kind f protection to put on the socket border or any other tip? I would like to thank you in advance.
Great question Mario! Sleeve wear at the socket trim line can be a common issue. WillowWood offers a couple sleeve options to address this. The Alpha Hybrid Sleeve features a polyurethane pad on the inside of the sleeve. The pad aligns with the socket brim line and helps reduce damage to the seal due to impacts in the brim area. Our LimbLogic Sleeve has a repositionable silicone cuff that allows users who are using elevated vacuum to fix a leak immediately. The cuff may be repositioned so that should a user puncture the sleeve, they can rotate the cuff and immediately regain an airtight seal. To see all WillowWood’s suspension sleeve options, visit the following page of our site: https://www.willowwood.com/products-services/suspension/suction-sleeves/
I have a below knee congenital amputation and use a willow wood liner. I have a very bony prominence on the distal end. The liner is very comfortable, BUT, with any gel liner, I’ve experienced extreme pain on the distal end when sitting down. It feels like a terribly painful “hickey’ feeling for lack of better words. It is unbearable by all means. If I wear simple prosthetic socks I do not experience this, but the liner is much more comfortable on the entire leg when walking. I am at a loss for how to fix this debilitating issue and am looking for any advice to resolve this.
Hi Mike, please email email@example.com and he’ll direct your question to a clinician.